Method of correcting the working thickness of a printing- element



H. W. HACKER. METHOD OF CORRECTING THE WORKING THICKNESS OF A PRINTING ELEMENT APPLICATION FILED JUNE 20. I918.

Patented Sept.

2 SHEETS-S H. W. HACKER.

METHOD OF CORRECTING THE WORKING THICKNESS OF A PRINTING ELEMENT.

APPLICATION FILED 111N520. I9I8.

PatentedSept. 23, 1919.

2 SHEETS-SHEET 2.

UNITED STATES PATENT OFFICE.

HORACE W. HACKER, OF CHICAGO, ILLINOIS.

METHOD OF CORRECTING THE WORKING THICKNESS OF A PRINTING- ELEMENT.

To all whom it may concern:

Be it known that I, Horace XV. HACKER, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a certain new and useful Improvement in Methods of Correcting the l/Vorking Thickness of a Printing Element, of which the following is a full, clear, concise, and exact description.

My invention relates to printing and has for its object the provision of a method for making the working thickness of a printing element substantially correct throughout the printing area. The method consists in measuring the working thickness of the printing element at a multiplicity of places substantially evenly distributed through the printing area and disposing patches of compensating thicknesses respectively in working alinement with the measured portions of the printing element.

The method of the invention is of particular service in correcting the composite working thickness of a printing plate and its mounting although the invention is not to be limited to such a use. I preferably temporarily place a mounting sheet upon the printing plate and measure through the mounting sheet the composite working thickness of the printing plate and its mounting at a multiplicity of places which are substantially evenly distributed throughout the printing area. I dispose patches of compensating thicknesses upon the mounting sheet in positions respectively similar to the measured portions of said plate and its mounting and then relocate the patch supporting mounting sheet between the printing plate and its mounting with the COIII- pensating patches thereon respectively in working alinement with the measured por tions of the printing plate and its mounting. In order to avoid ridges the patches are laterally spaced apart to afford gaps therebetween.

I will explain my invention more fully by reference to the accompanying drawings showing the preferred embodiment thereof and in which Figure 1 illustrates a print-- ingplate and its mounting temporarily assembled by a few tacks and above the plate there'is shown a mounting sheet which is to be placed temporarily upon the plate; Fig. 2 is a cross sectional view of a part of the plate and a portion of its mounting; Fig. 3 illustrates the mounting sheet placed tem- Serial .No. 241,083.

porarily upon the .plateyFig. 4 is a sectional View showing portions of the parts shown in 3; Fig. 5 is a View illustrating one device that may be employed for measuring the working thickness of a printing element; Fig. 6 is aview of a part of the mechanism shown in Fig. 5, portions being shown in section and a part being removed to illustrate the mechanism; Fig. 7 is a sectional view illustrating a detail of construction .of the measuring device shown in Fig. 5; Fig. 8 is a sectional View of a part of the plate and block with compensating patches and their mounting sheet upon the plate; Fig. 9 is a perspective view illustrating a mounting sheet with the patches thereonbetween the plate and block that are illustrated in separated relation; and Fig. 10 is a sectional view of a part of the plate and block with compensating patches and their mounting sheet between the plate and block.

Like parts are indicated by similar characters of reference throughout the different figures.

The drawings illustrate the employment of the method of my invention in conjunction with a printing plate 1 which is temporarily Specification of Letters Patent. Patented Sept, 23, 1919 Application filed June 20. 1918. I i

mounted upon the wooden block 2 by means of a very few tacks 3. The temporarily mounted plate and its mounting block are placed in a. planer which planes the bottom face of the block to bring the aggregate working thickness of the plate and block two-one-thousandths of an inch below type high thickness at the places of greatest aggregate thickness. A thin coating of printers ink is then placed upon the printing face of the plate 1 whereafter a mounting sheet 4 is applied to the plate and is iemporarily held thereon by the ink. This.

mounting sheet is preferably French folio paper, having a thickness of two-one-thousandths of an inch. This paperis desirably supplied by those who practice the method in large sheets which are ruled 0r perforated along crossed lines 5 in order that sheets of approximately suitable dimensions may be quickly formed.

The printing platel, the mounting block 2 therefor, and the mounting sheet 4 upon the plate are next placed in a thickness measuring machine to determine to what extent the aggregate working thickness of the plate and mounting is lacking. A machine which would readily serve this purpose is disclosed in the patent to J amesB. Replogle,

1,171,646, dated February 15, 1916. This machine includes an engaglng element or bed 6 (Fig. '5) upon which the block 2 is d. A follower 7 is mounted to be supporte engageable with the printing face of the gage 9 is mounted independently of the follower carrier 8 upon a bracket structure 10. The plunger 11 of the micrometric gage rests upon the top ofthe follower and 1s maintained in engagement therewith by a v spring 12 (Fig. 6). The plunger isprovided with a rack 13 in actuating relation to a trainof gears 14, the final wheel ofthe gear train being upon a shaft thatcarries an indicating needle 15. ,A weight 16 is provided for applyingthe follower 7 to-the plate 1 with heavy working-like pressure to simulate as far as possible the actual condition which obtains when the plate is in printing operation. This weight is carried upon'the forward end of a crank arm 17 in fixed relation with a rotatable sleeve 18 having a bore co-axial with a shaft 19. The intermediate portion of the sleeve 18 is enlarged and has a circular periphery which eccentric with'respect to the shaft 9, this eccentric being thus 'in fixed angular relation'with the crank arm- 17. The eccentric portion of the sleeve 18 is surrounded'by an eccentric strap 20 at the lower end of'a pitman 21 whose upper end is connected with an intermediate portion of the follower support 8 which is preferably mounted upon the bracket 10 at 8 When the crank arm 17 is raised the eccentric will be shifted to raise the front end of the follower support 8 and when the crank arm is lowered the follower support willbe consequently lowered. The weight 16, through the intermediation of the crank arm 17, the pitman 21, and the followersupport 8, presses the follower 7 upon the mounting sheet 4 and the plate 1 and block 2 beneath the mounting sheet with the desired degree of heavy working-like pressure whereby the particular portion being measured is brought to the thickness it will assume in its working environment. Each time a new measurement is taken the forward end of the, crank arm 17 is lifted to permit the desired repositioning of the plate'beneath the follower, whereafter the crank arm is generally lowered until the follower rests upon the mounting sheet, whereupon the arm will be released to permit the weight to press the follower upon the mounting sheet with the requisite pressure. The plunger 11 of the micrometric gage will follow the movement of the follower to bring the indicating needle 15 to the working thickness indicating position which may be the correct thickness or less than the correct thickness.

The measurements are taken at a multiplicity of places substantially evenly dis tributed throughout the printing area. A patch 22, of compensating thickness is placed upon the mounting sheet at each place wherebe printed thereon or the patches may be of different colors, each color corresponding to a thickness. 7 For example, patchesof a pink color would be one-one-thousandth of an inch thick, whlte patches two one-thousandths of an inch thick, and blue patches three one-thousandths of an inch thick, etc. The deficiency in the working thickness occurring at each place measured may be penciled On the mounting sheet, as indicated in Fig. 8, and when there is no deficiency such a condition may also be noted on the mount ing sheet for the sake of assurance. Fig. '8 indicates two places where the worklng thickness is one One-thousandth of an inch deficient, three places where such thickness is two onethousandths of an inch deficient,

five places where it is three o1ie' -tl1 ousa11dths of aninch deficient, three places where it is four one-thousandths of an inch deficient,

one place where it is five one-thousandths'of an inch deficient, and siX places where it is not deficient. No compensating patches are I placed upon the mounting sheet where the" working thickness'is not deficient. A pink patch of paper one one-thousandth of an inch thick is pasted on the mounting sheet at eachplace where the working thickness is one one-thousandth of, an inchdeficient; a

whitepatch of paper two one-thousandths an inch thick is pasted on the mountingsheet at each place where the working thickness is two one-thousandths of an inch deficient;

a blue patch of paper three one-thousandths of an inch thick is, pasted on the mounting sheet at each place where the working thickness is three one-thousandths of an inch de ficient; a red patch of paper four one-thousandths of an inch is pasted on the mounting sheetat each place where the working thickness is four one-thousandths of ,an inch deficient; and a green'patch of paper five are thus disposed in positions respectively similar to the measured portions of the plate and its mounting and after this step in the method has been accomplished the tacks 3 y are removed and the printing plate is lifted from its mounting block whereafter the patch supporting mounting sheet is relocated from the top of the printing plate to a place between the printing plate and its block (Fig. 7) and in such position that the compensating patches on the mounting sheet are respectively in workin alinement with the measured portions of t e printin plate and its mounting; that is, these patc ies are so located that they are underneath those positions which they initially occupy above the plate. After the mounting sheet has been properly relocated from the top of the printing plate the printing plate is firmly secured to its mountino block. These patches thus bring the printing plate to a proper working thickness throughout its printing area. The patches are desirably laterally spaced apart to afford the gaps therebetween that are illustrated in Fig. 7 to prevent theformation of ridges at the adjacent edges of adjacent patches. By means of my invention patches of compensating thickness are respectively disposed in working alinement with the measured portions of the printing element, the process being very simple and accurate.

While I desirably employ patches each individual to a measured portion of the printing element that is deficient in working thickness, I do not wish to be limited to such individual patches.

While I have herein shown and described one form of apparatus with which to practise my method and one type of printing element involved in the method, I do not wish to be limited to such apparatus nor to the nature of printing element in connection with which the method is used, but having thus described my invention I claim as new and desire to secure by Letters Patent the following 1. The method of making the composite working thickness of a printing plate and its mounting substantially correct throughout the printing area which consists in temporarily placing a mounting sheet upon the printing plate; measuring through the mounting sheet the composite Working thickness of the printing plate and its mounting at a multiplicity of places substantially evenly distributed throughout the printing area; disposing patches of compensating thicknesses upon said mounting sheet in positions respectively similar to the measured portions of said plate and its mounting; and

relocating said patch supporting mounting sheet between the printing plate and its mounting with the compensating patchesthereon respectively in working alinement with the measured portions of the printing plate and its mounting.

2. The method of making the working thickness of a printing element substantially correct throughout the printing area which consists in temporarily placing a mounting sheet upon the printing element; measuring through the mounting sheet the working thickness of the printing element at a multiplicity of places substantially evenly distributed throughout the printing area; disposing patches of com ensating thicknesses upon said mounting sleet in positions respectively similar to the measured portions of the printing element; and relocating said patch supporting mounting sheet with the compensating patches thereon respectively in working alinement with the measured portions of the printing element.

3. The method of making the composite working thickness of a printing plate and its mounting substantially correct throughout the printing area which consists in temporarily placing a mounting sheet upon the printing plate; measuring through the mounting sheet the composite working thickness of the printing plate and its mounting at a multiplicity of places; disposing patches of compensating thicknesses upon said mounting sheet in positions respectively similar to the measured portions of said plate and its mounting; and relocating said patch supporting mounting sheet between the printing plate and its mounting with the compensating patches thereon respectively in working alinement with the measured portions of the printing plate and its mounting.

4. The method of making the working thickness of a printing element substantially correct throughout the printing area which consists in temporarily placing a mounting sheet upon the printing element; measuring through the mounting sheet the working thickness of the printing element at a multiplicity of places; disposing patches of compensating thicknesses upon said mounting sheet in positions respectively similar to the measured portions of the printing element; and relocating said patch supporting mounting sheet wlth the compensating patches thereon respectively in working alinement with said measured portions of the printing element.

5. The method of making the composite working thickness of a printing plate and its mounting substantially correct throughout the printing area which consists in measuring such composite working thickness at a multiplicity of places substantially evenly distributed throughout the printing area;

and disposing patches of compensating thicknesses upon a mounting sheet and between the plate and its mounting and respectively in working alinement with the mea'sured portions of the printing element and mounting.

- 6. The method of making the working thickness of a printing element substantially correct throughout the printing area which consistsin measuring the working thickness oftjhe printing element at a multiplicity of places substantially evenly distributed through the printing area; and disposing patches of compensating thicknesses upon a -mounting sheet and respectively in working porarily placing a mounting sheet upon the printing plate; measuring through the mounting sheet the composite Working thickness of the printing plate and its mounting at a multiplicity of places substantially evenly distributed throughout, the printing area; disposing laterally spaced apart patches of compensating thicknesses upon said mounting sheet inpositions respectively copies of this patent may be obtained for similar to the measured portions of said plate. and its mounting; andrelocating said patch supporting mounting sheet between the printing plate and its mounting with the compensating patches thereon respectively in working alinement with the meas- V ured portionsof the printingjplate and its mounting. v w

8. The method of making the working thickness of a printing element substantially correct throughout-the printing area which consists in temporarily placing a mounting sheet upon the printing element; measuring through the mounting sheet the working thickness of the printing element at a multiplicity of places substantially evenly disi tributed throughout the printing area; dis-L posing laterally spaced apart patches of compensating thicknesses upon said mounting sheet in positions respectively similar to the and relocating said patch supporting mounting sheet with the compensating patches thereon respectively in working alinement with the measured portions of the printing element.

measured portions of the printing element;

In witness whereof, I hereunto subscribe" my name this 29th day of May A. D., 1918.

HORACE W. HACKER.

five cents each, by addressing the Commissioner of Patents.

Washington, D. 03 

